Princess Anne’s ex-husband has told friends that he wants to be “happy” before he dies, as he justified leaving his second wife for a younger woman.

Captain Mark Phillips, 63, who is father of the Princess Royal’s two children Zara and Peter, announced that he was leaving Britain to set up home in Florida with 35-year-old Olympic equestrian Lauren Hough.

Capt Phillips and his wife Sandy, 58, who have a 14-year-old daughter, Stephanie, have separated and started divorce proceedings.

The Daily Telegraph reported that he told friends: “I might only be alive for another five or 10 years, so I might as well be happy.”

Two years ago, Capt Phillips said that he planned to give up his position as chef d’équipe of the US team after the London Olympics because of the demands of transatlantic commuting.

However, he is now understood to be in the process of permanently moving to the US from his farm in Cherington, near Tetbury, Gloucestershire. Sources close to Miss Hough said the couple began house-hunting after she sold her Palm Beach home last month.

Capt Phillips’s solicitors CKFT, confirmed the separation in a statement: “Captain and Mrs Mark Phillips are separating and divorce proceedings have commenced. The couple have a daughter, aged 14, and the care and support of her is Capt Phillips’s main concern at this sensitive time.”

Mark Phillips met both Princess Anne and his second wife through horse riding. The Princess Royal rode for Britain in the 1976 Olympics in Montreal, four years after Capt Phillips won his gold medal at the Munich Olympics.

Sandy Phillips, whose maiden name was Pflueger, was part of the US dressage team at the 1984 Los Angeles Olympics, while Miss Hough was part of the US team at the 2000 Sydney Olympics.